The present invention relates to a system for handling compressible articles. The system is designed particularly for use in loading relatively large volume bags of glass fibre insulation but is not limited to the use in such field. The system is particularly suitable for handling large numbers of bulky bags having uniform size and being compressible.
In different manufacturing fields, it is desired to conveniently and quickly load into a cargo container of a truck or the like a large number of loaded bags, the bags being arranged in tier fashion in several rows across the width of the cargo compartment of the truck, with the elongation of the bags following the elongation of the cargo compartment.
It is well known in the art of material handling that forklift trucks having a so called pusher are advantageous in that they allow a quick engagement with a cargo and a convenient unloading of the cargo from the forklift by actuating the pusher plate to move forwards of the truck thus removing the load from the forklift. An embodiment of such pusher plate is shown, for instance, in U.S. Pat. No. 2,388,458 issued Nov. 6, 1945 to J. R. Alfonte. Another patent which shows that the basic principle of a pusher plate is well established in the art is U.S. Pat. No. 3,788,507 issued Jan. 29, 1974 to H. Voss. U.S. Pat. No. 4,284,384 is another example of a pusher plate mechanism connected with a forklift mechanism. All of the above patents show that the pusher plate arrangement belongs to a common general knowledge and many embodiments thereof have long been used in the art.
It is also known to provide a load engaging and gripping apparatus having side walls which are operatively associated with suitable, usually hydraulic, mechanism which grips the sides of a load, whereupon the load can be lifted and pivoted about a longitudinal, normally generally horizontal axis to suitably manipulate the handled load. U.S. Pat. No. 3,971,584, issued July 27, 1976 to A. W. Duncan is one of many examples of such a load engaging and gripping apparatus. Another example of such apparatus which is adapted to engage a load such as an upwardly elongated box near the top thereof and at the bottom, is shown in U.S. Pat. No. 3,174,639, issued Mar. 23, 1965 to D. B. Chase et al.
It is also known from the art of handling loads that the problem of economically handling loads while placing same into the cargo compartment of a truck trailer or the like has long been the subject of research and development. Thus, U.S. Pat. No. 3,788,496, issued Jan. 29, 1974 to Webb et al. shows a method and apparatus in which cartons are assembled and loaded into a truck or a railway car. Briefly, the apparatus includes a turning mechanism in combination with a conveyor. The turning mechanism orients a plurality of cartons into unit stacks which are then assembled into tiers of stacks having predetermined size to fit a given cargo space. Mechanical means are then used for inserting the assembled stacks into available cargo space to make a tight fit. The disadvantage of this system, as compared with the present invention, is mainly seen in complexity of the overall arrangement as a special, separate mechanism is required to be place between a forklift truck and the cargo compartment, as best shown in FIG. 14 of the reference.
Another known prior art dealing with the problem of handling bagged articles, in this case bagged mail, is described in U.S. Pat. No. 3,266,645 issued Aug. 16, 1966 to J. E. McWilliams. In this arrangement, the system comprises a plurality of sideless carts, each cart having a platform and two upright end walls so dimensioned as to generally correspond to the width of the box-shaped cargo is a transport vehicle. The platform and the end walls fixedly secured to same are arranged to be lifted from the carriage of each respective cart by a forklift truck, whereupon the forklift truck brings the whole arrangement of the platform and side walls into the cargo compartment. The forklift truck is equipped with a pusher plate and when the load is brought within the cargo compartment, the pusher plate is used to unload the load of bags from the platform. Then the forklift truck removes the empty platform from the cargo truck and places same back onto the carriage of the cart and proceeds with lifting the platform of the next cart. This arrangement eliminates the need of an intermediate arrangement such as shown in the Webb et al patent referred to above. However, it also eliminates the advantage of the Webb et al arrangement, namely the sideways compression of the articles before their placement within the cargo compartment. Moreover, the handling is relatively cumbersome since the operator of the cart must follow a relatively complex cycle, namely that of pick up of the platform from a cart, delivery of the load into the cargo compartment, return back to the cart, and the deposit of the empty platform back onto the carriage of the cart.